Friday, January 29, 2010

On January 11, a large missile streaked upward from a test site in China. The missile rocketed beyond the atmosphere and struck another similar missile launched from a separate site. Later that day, the official Xinhua news agency announced a ‘test on ground-based midcourse missile interception technology.’

‘The test has achieved the expected objective,’ Xinhua proclaimed. ‘The test is defensive in nature and is not targeted at any country.’

It was a seemingly impressive accomplishment--and apparently a big surprise to Western governments. To date, just one nation has managed to fire one missile to intercept another outside Earth's atmosphere: the United States. And that was after some 20 years of concerted technology development. Today the United States spends around $10 billion a year developing and buying missile-defense equipment, yet has hit another missile in exo-atmospheric tests on just a handful of occasions. The Chinese test seemed to represent a huge step towards eliminating the US lead.

It's unclear, however, how realistic the Chinese test was and how advanced the Chinese missile-defense technology truly is. It's equally unclear what exactly the Chinese missile interceptor is for.

These uncertainties are not unusual. The whole field of missiles and missile defense is notorious for its political theater. Nations will fund, buy or just plan for ballistic missiles and ballistic-missile defenses--however technically troubled or operationally impractical--solely for posturing. ‘These things tend to be tools of international politics,’ says Phil Coyle, an expert in missiles and missile defenses.

By firing just a handful of ballistic missiles, Iraq was nearly able to draw Israel into the 1991 Gulf War, which could have shattered the Western-Arab alliance arrayed against Iraq. North Korea, Iran and China all field ballistic missiles to back up their rhetoric towards South Korea, Israel and Taiwan, respectively. By the same token, systems that promise to render impotent these politically-empowering ballistic missiles carry much of the same weight in the halls of diplomacy and at the bargaining table.

For that reason, missile defenses are also big business. The US arms industry earns billions of dollars a year exporting various command systems, radars, launchers and interceptors associated with missile defense. In one of the biggest recent deals, last autumn Turkey announced plans to spend $8 billion on US-made PAC-3 missile interceptors.

States ringing heavily missile-armed nations are the best customers. The United Arab Emirates, Kuwait and Saudi Arabia all have bought PAC-3 interceptors, owing to Iran's growing missile force. South Korea bought PAC-3s and sea-based SM-2s, and Japan bought PAC-3s and seaborne SM-3s, both to contend with North Korea. Taiwan is buying PAC-3s to defend against China.

Was the Chinese test for real? Is the system meant to boost Beijing's position as it jockeys for influence over Taiwan? Was the point to send a signal to some other strategic rival--the United States perhaps, or India? Is the interceptor meant for export as part of a burgeoning commercial arms catalogue?

‘The bottom line is that people don't know for sure what's motivating this,’ says Michael Swaine, an analyst with the Carnegie Endowment for International Peace in Washington, D.C. And considering how the Americans have been working on their own missile defenses, good answers regarding the Chinese system could be years in coming. Just one thing is certain: whatever their operational reality, whatever the rationale behind their development, missile defenses represent an important and growing concern for the whole world and in particular, Asia.

The article goes on. I have my opinions (they want the capability as much as some of us do), but they are not the mainstream. Main, also, because I think the capability is worth having.

Using the most powerful laser system ever built, scientists have brought us one step closer to nuclear fusion power, a new study says.

The same process that powers our sun and other stars, nuclear fusion has the potential to be an efficient, carbon-free energy source—with none of the radioactive waste associated with the nuclear fission method used in current nuclear plants.

Thanks to the new achievement, a prototype nuclear fusion power plant could be operating within a decade, speculated study leader Siegfried Glenzer, a physicist at Lawrence Livermore National Laboratory in California.

Glenzer and colleagues used the world's largest laser array—the Livermore lab's National Ignition Facility—to heat a BB-size fuel pellet to millions of degrees Fahrenheit.

"These lasers are pulsed, and for a very short amount of time"—one ten-billionth of a second—"the power they produce is more than all the power generated by the entire electrical grid of the United States" at any given moment, Glenzer said.

The test confirmed that a technique called inertial fusion ignition could be used to trigger nuclear fusion—the merging of the nuclei of two atoms of, say, hydrogen—which can result in a tremendous amount of excess energy. Nuclear fission, by contrast, involves the splitting of atoms.

The laser demonstration means scientists are now much closer to triggering nuclear fusion in a controlled setting—something that's never been done before and which is necessary if fusion is to be harnessed for energy.

Wow. This is really kewl and damned depressing at the same time. A bit of background is available here.

depressing first. The NIF has waaaaaaaaaaaaaaay over budget. It's waaaaaaaaaaaaaaaaaaay behind schedule. In fact, if not for Shrub, I suspect it would have been canceled even with its supposed place in our testing regime. I know a nontrivial number of physicists, including those in the fusion program, that are annoyed with this: it sucks down money, they feel, is better spent elsewhere.

The damned kewl part is that we'er a step closer to inertial confinement fusion. While probably not the best way to produce power unlike the MHD fusion. However, it is INFINITELY closer to what we need for fusion drives in space. Now, assembling this is space is going to be a stone cold...monster...but once you have, you can get some impressive results for propulsion.

Potential irony here: we could get fusion drives long, long before we get fusion reactors.

Oh, note, maybe there's a reason to get that lunar He3 after all, James.

The great big militaria news is...the T-50/PAK-FA has flown. First off, let me state congratulations to the Russian engineers and techs that got this off the grown. Not so easy to do, especially working where and what you have. Let's see how easy it is to transition into production.

Some very good posts on the subject are here, here, and here. A video in that last one.

That said, let me make a few observations.

Let me state that unless this is a first iteration of multiple prototypes, do NOT expect this to be as stealthy as the F-22 or probably even the F-35. The reason being that if you noticed that the contours are not quite right for it. If there are multiple iterations of prototypes (for the air frame) then this could end up very stealthy.

Shaping is not the only issue here. Composites are also important, but it is really, truly important that they get their material science right. On the one hand, composites have come down in price and pretty easy to work with as we are about to with Team Phoenicia (c'mon tax return!). On the other hand, composite MatSci is not a field that the Russians are noted for...at all.

Furthermore, those nozzles. Dude. IR signature from hell.

Equally important for a 5th generation fighter is the sensor suite and integration. The Soviets, for their time, were pretty good with sensors. Not the best, but enough to cause heart burn and nervousness. A lot of tech has changed since the USSR went poofta.

The side view of the T-50 reminds me of the YF-23 for some reason.

Those renderings from some time back, well, looks like they were damned near spot on. At least for one of the designs. Interesting that.

Brain size is a key adaptive trait. It is often assumed that increasing brain size was a general evolutionary trend in primates, yet recent fossil discoveries have documented brain size decreases in some lineages, raising the question of how general a trend there was for brains to increase in mass over evolutionary time. We present the first systematic phylogenetic analysis designed to answer this question.Results

We performed ancestral state reconstructions of three traits (absolute brain mass, absolute body mass, relative brain mass) using 37 extant and 23 extinct primate species and three approaches to ancestral state reconstruction: parsimony, maximum likelihood and Bayesian Markov-chain Monte Carlo. Both absolute and relative brain mass generally increased over evolutionary time, but body mass did not. Nevertheless both absolute and relative brain mass decreased along several branches. Applying these results to the contentious case of Homo floresiensis, we find a number of scenarios under which the proposed evolution of the Homo floresiensis brain appears to be plausible, dependent on body mass and phylogenetic position.Conclusions

Our results confirm that brain expansion began early in primate evolution and show that increases occurred in all major clades. Only in terms of an increase in absolute mass does the human lineage appear particularly striking, with both the rate of proportional change in mass and relative brain size having episodes of greater expansion elsewhere on the primate phylogeny. However, decreases in brain mass also occurred along branches in all major clades, and we conclude that, while selection has acted to enlarge primate brains, in some lineages this trend has been reversed. Further analyses of the phylogenetic position of Homo floresiensis and better body mass estimates are required to confirm the plausibility of the evolution of its small brain mass. We find that for our dataset the Bayesian analysis for ancestral state reconstruction is least affected by inclusion of fossil data suggesting that this approach might be preferable for future studies on other taxa with a poor fossil record.

There's a small war over the evolution of the Monotremes. It was suggested that the echidna recently branched off from the platypus family. Recently means, btw, around the Paleogene-Neogene boundary. The original paper that suggested it is here. This caused a response. There has now been a response to that response.

The colour of some feathers on dinosaurs and early birds has been identified for the first time, reports a paper published in Nature this week.

The research found that the theropod dinosaur Sinosauropteryx had simple bristles – precursors of feathers – in alternate orange and white rings down its tail, and that the early bird Confuciusornis had patches of white, black and orange-brown colouring. Future work will allow precise mapping of colours and patterns across the whole bird.

Mike Benton, Professor of Palaeontology at the University of Bristol, said, "Our research provides extraordinary insights into the origin of feathers. In particular, it helps to resolve a long-standing debate about the original function of feathers – whether they were used for flight, insulation, or display. We now know that feathers came before wings, so feathers did not originate as flight structures.

"We therefore suggest that feathers first arose as agents for colour display and only later in their evolutionary history did they become useful for flight and insulation."

The team of palaeontologists from the University of Bristol, UK, the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing, University College Dublin and the Open University report two kinds of melanosomes found in the feathers of numerous birds and dinosaurs from the world-famous Jehol beds of NE China.

Melanosomes are colour-bearing organelles buried within the structure of feathers and hair in modern birds and mammals, giving black, grey, and rufous tones such as orange and brown. Because melanosomes are an integral part of the tough protein structure of the feather, they survive when a feather survives, even for hundreds of millions of years.

This is the first report of melanosomes found in the feathers of dinosaurs and early birds. It is also the first report of phaeomelanosomes in fossil feathers, the organelles that provide rufous and brown colours.

These discoveries confirm the substantial body of evidence that suggests birds evolved through a long line of theropod (flesh-eating) dinosaurs. It also demonstrates that the unique assemblage of characters that make a modern bird – feathers, wings, lightweight skeleton, enhanced metabolic system, enlarged brain and visual systems – evolved step-by-step over some 50 million years of dinosaur evolution, through the Jurassic and Cretaceous periods.

"These discoveries open up a whole new area of research", said Benton, "allowing us to explore aspects of the life and behaviour of dinosaurs and early birds that lived over 100 million years ago.

"Furthermore, we now know that the simplest feathers in dinosaurs such as Sinosauropteryx were only present over limited parts of its body – for example, as a crest down the midline of the back and round the tail – and so they would have had only a limited function in thermoregulation.

"Feathers are key to the success of birds and we can now dissect their evolutionary history in detail and see how each feather type – and the fine detail of feather structure – was acquired through time. This will link with current work on how the genome controls feather development."

Tuesday, January 26, 2010

The computer lab makes me gag. So does their treatment of computer models. Precipitation in the models is being misrepresented as well. I'm tempted to tack on the bad science label here because of it.

It's also not as original as I had thought it was going to be. I realize that they only have a limited amount of time but the simplicity of the ecosystems is irritating as well. This was a problem on virtually any faux documentary about past or alien ecosystems, actually.

Political turmoil, a brain drain of scientists and waning interest have transformed Russia from a nation that launched the first satellite into an increasingly minor player in the world of science, according to a Thomson Reuters report released on Tuesday.

An analysis of research papers published by Russian scientists shows an almost across-the-board decrease, which reflects Russia's shrinking influence not only in science but in science-based industries such as nuclear power, the authors of the Thomson Reuters report said.

"Russia's research base has a problem, and it shows little sign of a solution," the report reads.

"Russia has been a leader in scientific research and intellectual thinking across Europe and the world for so long that it comes not only as a surprise but a shock to see that it has a small and dwindling share of world activity as well as real attrition of its core strengths."

[...]

Russian research accounts for about 2.6 percent of the world's papers published in journals indexed by Thomson Reuters over five years, the report found.

"For comparison, this is more than Brazil (102,000 papers, 2.1 percent of world) but less than India (144,000 papers, 2.9 percent) and far less than China (415,000 papers, 8.4 percent)."

The main focus was on physics and chemistry, with little research in agriculture or computer science.

[...]

Cuts in funding and an aging work force have not helped, the report said.

"By one 2007 account, a few of the best Russian research institutes have budgets for research amounting to 3-5 percent of comparably sized institutes in the United States," the report reads.

The average age for a member of the Russian Academy of Science is over 50, and the prestige of a field that gave birth to Sputnik as the ultimate expression of Cold War rivalry has plummeted. Just 1 percent of Russians polled in 2006 named science as a prestigious career.

Sad, isn't it?

To make things worse, this seems to be an xUSSR wide situation. In Ukraine, being a scientist was considered, frankly, pathetic. A business career or even a farmer was considered a preferable job. Scientists do not have any respect at all in my experience.

What killed the dinosaurs? Scientist Wang Haijun thinks the answer may be buried inside a 980-foot-long ravine in the Chinese countryside 415 miles southeast of Beijing where hundreds of the creatures may have huddled in the final moments before their extinction.

The fossils here -- more than 15,000 fractured, mangled and blackened bones from about 65 million years ago in the late Cretaceous period right before they went extinct -- support theories of a catastrophe. Global fires. Explosions. Climate change.

"This find is very important for understanding the very end of the age of dinosaurs," said James M. Clark, a paleontologist at George Washington University who has examined some of the fossils.

Sounds like they were killed in a blast to me, but those of you that know more of taphonomy will be possibly be able to correct the possible misconception.

One of the largest and most oft repeated complaints is "Where are the fossils?" (from the KT 'roid splat)

We may be looking at them there. In fact, if this is the result of the Chicxulub Impact, then...that might be the explanation as to why there are so few NorAm fossils in Montana at the time. Why? Think it through.

I'm eagerly waiting for the papers that are generated from the site...and the resulting verbal wars.

Governor Arnold Schwarzenegger suggested California could ease its crowded prison system by sending thousands of undocumented inmates to specially built jails in Mexico.

Speaking to reporters at the Sacramento Press Club, Schwarzenegger said California could ease its strained finances by a billion dollars if 20,000 illegal immigrants currently held in the state were housed across the border.

"I think that we can do so much better in the prison system alone if we can go and take, inmates for instance, the 20,000 inmates that are illegal immigrants that are here and get them to Mexico," Schwarzenegger said.

"Think about it -- if California gives Mexico the money. Not 'Hey, you take care of them, these are your citizens'. No. Not at all.

"We pay them to build the prison down in Mexico. And then we have those undocumented immigrants down there in prison. It would half the costs to build the prison and run the prison. We could save a billion dollars right there that could go into higher education."

A renewable-energy "oasis" slated to be built in 2010 may serve as a proving ground for new technologies designed to bring green living to the desert.

The planned research center is part of the Sahara Forest Project—but that doesn't mean it'll be built in Africa. Sahara means "desert" in Arabic, and the center is meant to be a small-scale version of massive green complexes that project managers hope to build in deserts around the globe.

(See pictures of the planned Sahara Forest Project reseach center.)

Experts are now examining arid sites in Australia, the U.S., the Middle East, and Africa that could support the test facility.

"The Sahara Forest Project is a holistic approach for creation of local jobs, food, water, and energy, utilizing relatively simple solutions mimicking design and principles from nature," said Frederic Hauge, founder and president of the Norwegian environmental nonprofit the Bellona Foundation.

For instance, special greenhouses would use hot desert air and seawater make fresh water for growing crops, solar energy would be collected to generate power, and algae pools would offer a renewable and easily transportable fuel supply.

In addition, planting trees near the complex would trap atmospheric greenhouse gases such as carbon dioxide while restoring any natural forest cover that has been lost to drought and timber harvesting.

(Related: "Africa-wide 'Great Green Wall' to Halt Sahara's Spread?")

"From my perspective as an environmentalist, this could be a game changer in how we produce biomass for food and energy, and how we're going to provide fresh water for the future," Hauge said. "I've never been so engaged and fascinated as I am now."

But not all experts are as enthusiastic about the project.

In terms of the reforestation plans, "trying to grow trees in the Sahara desert is not the most appropriate approach," said Patrick Gonzalez, a forest ecologist at the University of California, Berkeley's Center for Forestry. After all, even though it was literally green in the past, the Sahara was never heavily forested. (See an interactive Sahara map.)

"I can imagine that this scheme and type of technology in limited cases might work in certain areas like Dubai, where they're used to making palm-shaped islands and 160-story-tall buildings," Gonzalez said.

If the goal is restoring a desert's natural ecosystem, however, "it would be more effective, but less flashy, to work with local people on community-based natural-resource management."

The flighted ancestor of birds such as the Australian emu and cassowary became too heavy to fly after the extinction of dinosaurs made it safer to forage for food, a new study suggests.

The finding by Australian National University (ANU) biologist Dr Matthew Phillips and colleagues at Massey University in New Zealand also answers the mystery of how flightless birds managed to disperse across oceans.

Their work, published in the latest Systematic Biology journal, follows on from recent work that raised uncertainty about the "single ancestor" theory of the group of flightless birds, known as ratites.

Dr Phillips says ratites are a group of flightless birds that include the Australian emu and cassowary, African ostrich, New Zealand's kiwi and now-extinct moa, rhea from South America and the extinct elephant birds of Madagascar.

The study used molecular dating of the mitochondrial DNA from the moa, which stood 2.5 metres tall and weighed up to 250 kilograms, and found its closest relative to be the tinamous - a flighted bird the size of quail, found in South America.

Previously it was thought ratites all shared a common flightless ancestor about 80 million years ago and their worldwide dispersal occurred before the supercontinent of Gondwanaland broke up.

But Dr Phillips says the problem with this theory was that much of the continental break-up occurred well before the proposed common ancestor.

Fewer predators

The study, which also included DNA sequencing of 22 bird species including flightless and flighted birds, shows ratites became flightless around 65 million years ago.

This coincides with the extinction of dinosaurs in the Cretaceous-Tertiary event.

"Our study suggests that the flighted ancestors of ratites appear to have been ground-feeding birds that ran well," Dr Phillips said.

"In the absence of predators and with abundant food resources on the ground, there is a tendency for birds to evolve larger size and become flightless.

"We see this a lot on islands - dodos for example.

"Larger ground-feeding birds can be more efficient at turning food into growth and reproduction, but with size increase, comes the cost of flight becoming less efficient."

Dr Phillips says the study also throws doubt on the widely held view that the ratite's origins lie in the Gondwana supercontinent that included Africa, South America, Australia, New Zealand, India and the Antarctic.

Thursday, January 21, 2010

Writer's Note: This is another post in the alternate timeline we have been calling the Xenopermian. Zach Miller of When Pigs Fly Returns and I have been hashing this out for some time. Our previous posts are located here, here and here. The Xenopermian is an alternate timeline where the Permian Extinction, more specifically the Permian-Triassic Mass Extinction, does not happen. What would have life been like through an extended Permian with a changing and evolving Paleozoic ecology.

That said, Zach and I are now exploring a a faux scientific controversy. This creature does not exist. It is not real. it is purely a product of our imaginations. Please do not start citing us as scientific literature for something doesn't exist. ok?

That said, we've been refering to the 'pseudocroc' for some time. The working name inspired how we'd introduce it to the TL and the public. Zach's post is here.

The scientific establishment has taken the view that the amniotes are a singular evolutionary event: all amniotes are evolved from a single common ancestor that developed the amniotic sack for protection against drying out the embryos prior to hatching. Our view is an alternate to this misguided belief. Our collective point of view is best summarized by its title: Paraphylitic Amniote Origination Theory or PAOT[1]. Our theory holds that the amniotic groups are all independently derived clades from basal reptilomorphs. Synapsida, Diapsida, Euryapsida, and Anapsida all independently evolved from reptilomorphs and that Amniota is a paraphyletic and not a natural group.

Xenosuchus prognathus is from the Late Xenopermian of the Ural Sea/East European Sea deposits of Russia, Xenosuchus is a moderate to large sized semi-aquatic post-reptilomorph para-amniote. It's preferred environment seems to have been in the brackish to salt water swamps where competition with the reigning freshwater clades of large labrynthodonts, other temnospondyls, and reptilomorphs were less common, if not absent.

Like most fossil vertebrates, its postcranial material is extremely sparse and undiagnostic. However, occurrence through various strata of very similar remains of postcranial Xenosuchus like remains helps identify their transition from freshwater to moderate to highly saline and their differentiation from other reptilomorphs to paraamniotic characteristics.

The cranial materials are very good for their unique and easily-identifiable characters. They demonstrate that the "amniotes" are very much paraphyletic in their origin. There is one primary characteristic of the Xenosuchus skull: there are traces ridges that adorn the skull. Very worn and residual while the organism was alive, these ridges are only viewable under close scrutiny and only on portions of the skull. They are most evident on the premaxiilla, but can also be seen on the fragment of the lower dentary.

Observed Xenosuchus ridging.(Figure a, Baird et al 2010)

These ridges are a derived trait of the temnospondyl clade, which are not considered by the mainstream to be ancestral to Amniota. Because this is a unique trait for the temnospondyls, this leads us to believe that the Xenosuchus lineage is derived directly from temnospondyls and only shares characteristics with Archosauria through parallel evolution. This lends overwhelming credibility to the idea that Xenosuchus fits our scenario of the “amniotes.” Xenosuchus is not a traditional archosaur nor a temnospondyl, but a derived postreptilomorph para-amniote.

Since our argument for Xenosuchus rests largely on the temnospondyl derived skull ridging, we must address why the ridging is only present on small parts of the cranial remains. Here we argue that this is due to two separate processes that are completely unrelated.

The first process is an evolutionary one. The xenosuchine lineage obviously loses the ridges completely by the beginning of the Paleozoic/Allozoic boundary, 200 mya. Our hypothesis is that the transition onto land reduced the necessity of the ridging which may have been used for nerves sensitive to water pressure differences to help with the capture of aquatic prey. Without the selection bias being for this sensory adaptation, eventually as the xenosuchids moved more and more terrestrial, this was lost. It should be noted that the Xenosuchus ridging differs from the standard temnospondyl pattern in that it is very fine grained and small such that if it was not being looked for, it would be overlooked. Xenosuchus is a rare find, a transitional fossil that it exhibits the more basal characteristics of its ancestry while generally being very derived.

The second process that reduced the ridging on the Xenosuchus cranial remains is preservational. Xenosuchus was discovered in sandstone and weathering and tumbling prior to the deposition would explain why the cranial ridging is present only in select, barely detectable locales in the fossil. Obviously, the skull tumbled in sand, possibly even the surf, prior to being laid to rest. However, we argue that the ridging is actually not a depositional artifact and that the deposition removed living organism’s skull ridging.

To test this hypothesis, we acquired multiple alligator skulls. We acknowledge that the alligators are a poor substitute, but there are few large paraamniote skulls that are of the appropriate shape. The gavial is a better approximation based on general morphology. However, our attempts to acquire sufficient crania were unsuccessful. Furthermore, the single skull we did acquire was simply too delicate for the experiment to proceed.

Meticulously, we used a laser engraver to etch in a pattern not unlike what we have detected in Xenosuchus. This took several attempts and ruined multiple skulls. Our success rate was 30%. Laser engravers are not generally meant to etch bone. The pattern covered the whole skull and was no more than 1mm deep and ¼ mm wide for the ridges and valleys.

Once we did get six successfully engraved skulls, we placed them in a tumbler with sufficient quantities of sand. The tumbler was made from a standard 55 gallon (214 liter) oil barrel. The tumbler was hooked up to an electric motor that provided 60 rpm for the tumbler chamber. One skull was placed with twenty-two pounds (ten kilograms) of sand and filled with water to capacity of water. The skull was left running in tumbler for 96 hours.

While not producing the exact same wear patterns as seen on Xenosuchus, our experiment produced not completely dissimilar results. The ridging was largely removed from the skull. We also found that the ridging that did remain was fairly similar to the cranial remains. We repeated the experiment five times with five alligator craniums and found that the results were very similar within an order of magnitude: sometimes the results were more thorough in removing the ridging. This removal was as much or more than the fossil. Other times it was less. We suspect that the differences are largely due to the variations in ridge depth and skull composition. No two skulls are exactly the same. Variations in size, shape, bone density and composition would all account for differing results.

One skull was placed in the tumbler until the ridging was completely and undetectably removed. The experiment did not run continuously. We interrupted the process every 24 hours to measure the removal of the ridging. The ridging was completely removed after 168 hours (7 days). This means that sometime between six and seven days the ridging was removed. In multiple instances, the skulls themselves were ruined. Often the jaws were smashed or the cranial remains were in a disarticulated state. This matched Miller et al’s observed state for the fossil cranial deposition. This constrains the time frame that the Xenosuchus remains were tumbled prior to deposition.

This experiment raises some interesting implications that support our hypothesis. The loss of ridging through depositional processes would indicate that more fossils may be of the para-amniote line than previous thought. More remains that have been cladisticly identified as archosaurs may in fact be of the Xenosuchine lineage. We feel that this deserves further, careful investigation. It could be that archosaurs as a whole are a paraphylitic, unnatural group and that this is not just constrained to the amniotes as a whole.

In any case, the discovery of the skull ridging on the Xenosuchus cranial fossil has uncovered a diagnostic feature that is constrained to the temnospondyls alone. This demonstrates that Xenosuchus was not an archosaur. This in turn demonstrates that “amniote” characteristics were acquired by multiple lineages independently and that amniotes are an unnatural group as such.

1. This is unfortunately pronounced as 'pout' by our detractors and adherents as 'Pouters'. We do not approve of this derogatory comment.

Tuesday, January 19, 2010

So, the election, round one, is over. Yushchenko got crushed. Now its between Yani and Timo in a run off since neither got more than 50%. It was 35% and 25% respectively. Timo's base of support was in the West. Yani's in the East, especially the Donbass. It'll be close, but either can win. As I have said before, Timo is like the Ann Coulter of Ukraine and Yani's...well...Nixon (bad side) crossed with ... Bush Jr.

Something that I truly hate about all of Ukrainian politics is that it has devolved into blocks purely based on personalities. The Block of Timoshenko, The Block of Lytvin, even the Party of Regions is really just the block of Yanukovich.

bleh.

My bet? Yani's gonna win. He won't be a Russian pawn, but the corruption will get worse and he'll make nice-nice with Darth Putin while trying his best to walk a careful line with the West.

The sediments of the Kimmeridge Clay Formation were deposited during the Late Jurassic between around 160 and 145 million years ago, the age of the reptiles. They are the main oil source rock in the North Sea. However, within this unit beds rich in organic matter are interspersed with organic-poor sediments. New evidence demonstrates that organic-poor sediments were probably caused by post-depositional loss of organic matter during so-called 'burn-down' events.

The Kimmeridge Clay Formation is named after the English village of Kimmeridge on Dorset's 'Jurassic Coast', a favourite haunt of fossil hunters. The sediments comprising the formation, which is particularly well exposed here, were probably deposited in shallow marine environment with an average water depth of 50-100 metres.

"We were particularly interested in the transition between organic-rich and organic-poor sediments," said Dr Ian Harding of the University of Southampton's School of Ocean and Earth Science at the National Oceanography Centre, Southampton (NOCS), and a member of the team that investigated the underlying processes.

A long-held hypothesis is that the organic-rich beds were the result of elevated planktonic productivity in sunlit surface waters, possibly accentuated by enhanced preservation of the resulting organic matter by the oxygen-depleted bottom waters resulting from this excess productivity.

A second possibility was that a cyclic rise and fall of the interface between oxygenated and oxygen-depleted waters was responsible for the transition between organic-rich and organic poor sediments. According to this theory, when oxygenated waters reached the seabed, organic matter already deposited would have been oxidised and degraded. These post-depositional 'burn down' events could have alternated with periods during which the bottom waters had little oxygen, favouring preservation of organic matter.

"The first theory emphasises changes in the amount of organic matter reaching the seabed, while the 'burn-down' theory puts more weight on the relative dominance of preservation or degradation after it has got there," said Dr Harding.

To distinguish between these two theories, he and colleagues from the University of Bremen and the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, analysed the chemical composition and organic content of a sediment core from a borehole in Swanworth Quarry in Dorset, originally drilled as part of the Natural Environment Research Council (NERC) Rapid Global Geological Events Project run by NOCS' Prof. John Marshall.

Monika Kodrans-Nsiah, a PhD student jointly supervised by Dr Harding and Dr Karin Zonneveld (Bremen) was responsible for analysing the fossilised organic cysts of various species of dinoflagellate, a group of tiny aquatic organisms, found in the sediments. Different dinoflagellate species are known to be adapted to different environmental conditions, so studying the distribution of 'dinocyst' fossils helps reconstruct past environments.

The lower part of the core was rich in organic carbon, with abundant dinocysts, and its chemical composition was indicative of anoxic conditions, implying that sediments were deposited and preserved in an oxygen-deficient environment.

However, the chemical composition of the uppermost sediments indicated the presence of oxygenated water when they were deposited. This transition was sudden, occurring at a drilling depth of 122.37 metres, but changes in organic content and dinocyst distributions were more gradual.

"It looks likely that influxes of well-oxygenated bottom water caused the oxidation and degradation of organic matter and cysts after they were deposited," said Dr Harding: "This would explain the gradual reduction in the amount of organic matter above the transition, and provide support for the idea of 'burn-down' events during the Jurassic."

Monday, January 18, 2010

European Space Agency (ESA) head Jean-Jacques Dordain says the agency does not plan any program rollbacks due to cash flow problems that are afflicting the agency, and will move aggressively to define a concept for a new heavy-lift launch vehicle that would succeed the Ariane 5.

Dordain says ESA spending has grown an average of 10 percent per year since 2006 as the agency has ramped up new programs approved at the 2005 and 2008 ministerial summits. The sum reached €3.35 billion ($4.8 billion) last year. Although this was well below the 2009 budget, fiscal shortfalls in a number of ESA member countries provoked by the ongoing financial crisis created a cash crunch, forcing the agency to borrow money to pay near-term payment obligations.

To resolve the cash flow matter, ESA will freeze spending at 2009 levels (except for Galileo FOC) through 2010 and 2011, Dordain says. In addition, the agency will attempt to negotiate new contracts with lower payments at contract signature and higher payments on delivery. Anticipated slippage in existing programs also is expected to help.

A further boost is anticipated from a new financial management system approved in December. The system, first agreed to at the 2005 summit with Galileo and other cooperative programs in mind, is intended to provide increased funding flexibility and afford cost savings, while bringing ESA practices in line with those of the European Union and other partner organizations.

Despite the payment freeze, Dordain insists the agency will not cancel any programs. On the contrary, it will seek to move forward several undertakings that are currently stalled, in particular the European Data Relay System, which ESA aims to deploy in partnership with a private operator. A final request for proposals is to be issued to the three bidders in February. The winner is to be named in May and a contract signed in November, Dordain says.

The new heavy-lift launch vehicle would replace the Ariane 5 around 2025. The European launch community says the changing market calls for a new vehicle sized more closely to fit government requirements and designed so that commercial launch needs are not central to its sustainability. The objective, Dordain says, is to arrive at the next ministerial summit in 2011 with a firm definition proposal for the new booster, known in ESA parlance as the New Generation Launcher (NGL) but commonly called the Ariane 6.

The undertaking received a major boost in December when it was named to benefit from a special French government bond issue. Valerie Pecresse, the minister in charge of space, says the bond issue will provide €250 million ($360 million) to begin definition of the Ariane 6, which is expected to cost €3.5 billion to €8 billion to develop.

Dordain says ESA has already begun studying Ariane 6 concepts with French space agency CNES and other member states using building blocks and funding provided through the Future Launcher Preparatory Program (FLPP). Dordain notes that many of the design choices remain to be made, including which type of propulsion system — cryogenic, storable propellant or advanced solid rocket — should be used. However, he says the new vehicle will almost certainly adopt the modular approach that French engineers have proposed, capable of launching three to six or seven metric tons — the upper limit of telecom satellites — to geostationary transfer orbit. This would shift the focus from dual launches, which have long been the hallmark of Arianespace, to the single launch approach followed by competing operators.

Wednesday, January 13, 2010

Astronomers have obtained the first direct spectrum – a “chemical fingerprint” – of a planet orbiting a distant, Sun-like star, providing direct data about the composition of the planet's atmosphere. An international team of researchers studied the planetary system around HR 8799 a bright, young star with 1.5 times the mass of our Sun, and focused on one of three planets orbiting the star. While the results were unusual and pose a challenge to current models of the exoplanet's atmosphere, the accomplishment represents a milestone in the search for life elsewhere in the Universe.

[...]

Bergfors added, “It took more than five hours of exposure time, but we were able to tease out the planet's spectrum from the host star's much brighter light.”

However, the spectra of the exoplanet's atmosphere shows a clear deviation between the observed spectral shape and what is predicted by the current standard models. “The features observed in the spectrum are not compatible with current theoretical models,” said MPIA's Wolfgang Brandner, a co-author of the study.

The models assume chemical equilibrium between the different chemical elements present in the atmosphere, and a continuous temperature profile (hotter layers below colder layers). At longer wavelengths (above 4 micrometres), the planet is significantly fainter than expected, which points to molecular absorption in its atmosphere. The simplest explanation is that the atmosphere contains less methane and more carbon monoxide than previously assumed.

“We need to take into account a more detailed description of the atmospheric dust clouds, or accept that the atmosphere has a different chemical composition than previously assumed,” Brandner said.

Contrary to scientists' predictions that, as the Earth warms, the movement of trees into the Arctic will have only a local warming effect, University of California, Berkeley, scientists modeling this scenario have found that replacing tundra with trees will melt sea ice and greatly enhance warming over the entire Arctic region.

Because trees are darker than the bare tundra, scientists previously have suggested that the northward expansion of trees might result in more absorption of sunlight and a consequent local warming.

But UC Berkeley graduate student Abigail L. Swann, along with Inez Fung, professor of earth and planetary science and of environmental science, policy and management, doubted this local scenario because, while broad-leaved trees are dark, they also transpire a lot of water, and water vapor is a greenhouse gas that is well-mixed throughout the Arctic.

Taking account of this in a standard model of global warming, the researchers discovered that, while broad-leaved trees do absorb some additional sunlight, the water vapor they pump into the atmosphere causes a more widespread warming.

"Broad-leaved deciduous trees are not as dark as evergreen trees and so are generally assumed to be less important. But broad-leaved trees transpire a lot more water through their leaves and are actually able to change the water vapor content and increase the greenhouse effect. As the air warms, it can hold more water vapor, and the greenhouse effect increases further," Swann said. "So, broad-leaved trees end up warming the entire Arctic."

More importantly, the researchers' model predicts that the increased water vapor would melt more sea ice, resulting in more absorption of sunlight by the open ocean and dumping more water vapor into the atmosphere. This positive feedback will warm the land even more and encourage faster, more efficient tree growth and perhaps a faster expansion of trees into the Arctic.

All told, the model predicts an additional 1 degree Celsius increase in temperature over the Arctic as a result of this effect. Global warming already is predicted to increase temperatures in the Arctic between 5 and 7 degrees Celsius within the next 100 years.

The analysis was reported Jan. 7 in the online Early Edition of the journal Proceedings of the National Academy of Sciences.

I'll find the paper later.

So, a minimum of 6 to 8 C increase in the Arctic average. I've heard much, much higher estimates that people are not willing to publish yet. ;)

Monday, January 11, 2010

India has begun development of lasers and an exo-atmospheric kill vehicle that could be combined to produce a weapon to destroy enemy satellites in orbit, the director-general of India's defense research organization said Jan. 3.

"The kill vehicle, which is needed for intercepting the satellite, needs to be developed, and that work is going on as part of the ballistic missile defense program," said V.K. Saraswat, director-general of the Defence Research and Development Organisation, which is part of India's Ministry of Defence.

In a televised press briefing during the 97th Indian Science Congress in Thiruvananthapuram, Saraswat said the program includes the development of lasers "which will be able to give you a concrete picture of the satellite, and use that picture to guide your kill vehicle towards that. That work has yet to be done."

On the heels of China's test fire and then ABM testing, this announcement pretty much seals that the high frontier is now open for militarization.

China announced that its military intercepted a missile in mid-flight Monday in a test of new technology that comes amid heightened tensions over Taiwan and increased willingness by the Asian giant to show off its advanced military capabilities.

The official Xinhua News Agency reported late Monday that "ground-based midcourse missile interception technology" was tested within Chinese territory.

"The test has achieved the expected objective," the three-sentence report said. "The test is defensive in nature and is not targeted at any country."

Monday's report follows repeated complaints in recent days by Beijing over the sale by the U.S. of weaponry to Taiwan, including PAC-3 air defense missiles. These sales are driven by threats from China to use force to bring the island under its control, backed up by an estimated 1,300 Chinese ballistic missiles positioned along the Taiwan Strait.

Communist-ruled China split with Taiwan amid civil war in 1949 and continues to regard the self-governing democracy as part of its territory. Beijing has warned of a disruption in ties with Washington if the sale goes ahead, but has not said what specific actions it would take.

China's military is in the middle of a major technology upgrade, spurred on by double-digit annual percentage increases in defense spending. Missile technology is considered one of the People's Liberation Army's particular strengths, allowing it to narrow the gap with the U.S. and other militaries that wield stronger conventional forces.

Xinhua did not further identify the system tested, although China is believed to be pursuing a number of programs developed from anti-aircraft systems aimed at shooting down stealth aircraft and downing or disabling cruise missiles and precision-guided weapons.

Such programs are shrouded in secrecy, but military analysts say China appears to have augmented its air defenses with homemade technologies adapted from Russian and other foreign weaponry. China purchased a large number of Russian surface-to-air missiles during the 1990s and has since pressed ahead with its own HQ-9 interceptor, along with a more advanced missile system with an extended range.

Foreign media reports in 2006 said Beijing had tested a surface-to-air missile in the country's remote northwest with capabilities similar to the American Patriot interceptor system. According to South Korea's Dong-A Ilbo newspaper, the test involved the detection and downing of both a reconnaissance drone and an incoming ballistic missile by an interceptor, adding that it appeared to mark the official launch of China's indigenous interceptor unit.

"There is an obvious concern in Beijing that they need an effective anti-ballistic missile defense in some form," said Hans Kristensen, an expert on the Chinese military with the Federation of American Scientists.

Staging a successful test "shows that their technology is maturing," Kristensen said.

Friday, January 08, 2010

Space Exploration Technologies Corp. has moved a step closer to the first flight of its Falcon 9 medium-lift launch vehicle with a 329-second test of its single-engine upper stage, mimicking the burn that will be required to put the company’s planned Dragon cargo vehicle in orbit.

That clears the way for the stage to be shipped from the SpaceX test site in Texas to Cape Canaveral Air Force Station, Fla., by the end of January for integration with the nine-engine Falcon 9 first stage on the path to a launch.

SpaceX founder and CEO Elon Musk said on the company’s Web site that integration could be finished in time for a February liftoff — in keeping with the most optimistic current plan — or it could move back as late as the end of April.

The Merlin engine generated 92,500 pounds of thrust during the static test Jan. 2, according to SpaceX. The company also has tested the staging mechanism on the composite interstage structure, using a mass-simulated upper stage atop the mechanical device, and has integrated the interstage with the first stage.

Work on the first Dragon flight vehicle also is progressing, the company said, with the pressurized portion of the qualification Dragon mated to its unpressurized “trunk.” After testing in Texas, that vehicle will be shipped to Cape Canaveral for integration with the Falcon 9, the company said.

Wednesday, January 06, 2010

Despite their political popularity, carbon tariffs will be next to impossible to implement effectively, and as such will do little to solve the climate problem.

In every US climate policy negotiation thus far, a major sticking point has been the issue of economic competitiveness. If the US, or indeed any country, independently imposes a price on carbon — through a cap-and-trade system or a carbon tax, for example — domestic industries automatically face higher costs than their international peers and could be at a competitive disadvantage. Rather than pay these costs, of course, US industry could relocate to countries without mandatory emissions targets. This 'carbon leakage' could cost the US jobs while failing to reduce global emissions, a lose–lose scenario.

For the majority of US industry, the introduction of climate policy would have a negligible economic impact. There are exceptions, however, most notably energy-intensive industries such as steel and cement. Fortunately, several policy mechanisms can be used to protect their competitiveness. The proposed US climate bill, America's Clean Energy and Security Act1, uses two: first, the bill aims to rebate the increased costs of carbon emissions to energy-intensive industries through free allocation of emissions allowances. Second, US industries that import energy-intensive goods from countries without a price on carbon are required to purchase emissions allowances for those goods equal to what they would have paid had the imports been manufactured domestically. This tariff, a type of border tax adjustment, ensures that importers do not gain a competitive advantage over other domestic industries. The idea of implementing border adjustment mechanisms is now gaining popularity in the European Union, where France and Germany argue it would protect domestic industry if other nations do not agree to cut their emissions.

But there are numerous arguments against implementing carbon tariffs: they may trigger a trade war with damaging consequences for domestic industry; they target emerging economies whose cooperation is vital for global climate policy; they protect only industry on the domestic market; and according to the World Trade Organization2 they may be illegal, depending on how they are implemented. These thorny issues have been discussed at length elsewhere3, 4, 5. Supporters of carbon tariffs claim that they have two main advantages: first, they protect domestic industry from competitive disadvantage. Second, because the tariffs apply only to countries without a price on carbon, they are a 'stick' to motivate other countries to legislate climate policy. Surprisingly, given the complications associated with a carbon tariff, few have asked whether the arguable advantages can ever be realized. Because of the impossibility of designing and implementing an effective tariff, we argue that they cannot.

An interesting article that needs a proper response. *scribbles it on the list* *sighs* Nearing completion of the Medea critique though. Thank all that's good and light. It'll need a revision, but its already 11 pages. Hopefully, it won't grow beyond that. Then Xenosuchus and a handful of other articles that I need to finish.

The most earthlike planet yet found around another star may be the rocky remains of a Saturn-sized gas giant, according to research presented today at the American Astronomical Society meeting in Washington.

"The first planets detected outside our solar system 15 years ago turned out to be enormous gas-giants in very tight orbits around their stars. We call them 'hot Jupiters,' and they weren't what astronomers expected to find," said Brian Jackson at NASA's Goddard Space Flight Center in Greenbelt, Md. "Now, we're beginning to see Earth-sized objects in similar orbits. Could there be a connection?"

Jackson and his colleagues turned to CoRoT-7b, the smallest planet and the most like Earth that astronomers have found to date. Discovered in February 2009 by the Convection, Rotation and Planetary Transits (CoRoT) satellite, a mission led by the French Space Agency, CoRoT-7b takes just 20.4 hours to circle its sunlike star, located 480 light-years away in the constellation Monoceros. Astronomers believe the star is about 1.5 billion years old, or about one-third the sun's age.

"CoRoT-7b is almost 60 times closer to its star than Earth, so the star appears almost 360 times larger than the sun does in our sky," Jackson said. As a consequence, the planet's surface experiences extreme heating that may reach 3,600 degrees Fahrenheit on the daylight side. CoRoT-7b's size (70 percent larger than Earth) and mass (4.8 times Earth's) indicate that the world is probably made of rocky materials.

"But with such a high dayside temperature, any rocky surface facing the star must be molten, and the planet cannot retain anything more than a tenuous atmosphere, even one of vaporized rock," Jackson said. He estimates that solar heating may have already cooked off several Earth masses of material from CoRoT-7b.

With the help of computer models that track the planet's mass loss and orbital changes, the researchers have turned back the planet's clock.

"There's a complex interplay between the mass the planet loses and its gravitational pull, which raises tides on the star," Jackson explained. Those tides gradually change the planet's orbit, drawing it inward in a process called tidal migration. But closer proximity to the star then increases the mass loss, which in turn slows the rate of orbital change.

After accounting for the give-and-take of mass loss and tidal migration, the team finds that CoRot-7b could have weighed in at 100 Earth masses -- or about the heft of Saturn -- when it first formed. At that time, it orbited 50 percent farther from its star than it does now.

The researchers also show that regardless of whether CoRot-7b started life as a Saturn-like gas giant or as a rocky world, the planet has probably lost many Earth masses of material since its formation.

"You could say that, one way or the other, this planet is disappearing before our eyes," Jackson said.

He suggests that similar processes likely have influenced many other exoplanets that lie close to their stars. In fact, several recent studies suggest that many hot Jupiters have undergone similar mass loss and tidal evolution, perhaps leaving behind remnant cores similar to CoRoT-7b.

"CoRoT-7b may be the first in a new class of planet -- evaporated remnant cores," Jackson said. "Studying the coupled processes of mass loss and migration may be crucial to unraveling the origins of the hundreds of hot, earthlike planets space missions like CoRoT and NASA's Kepler will soon uncover."

The mid-Silurian Major Mitchell Sandstone of the Grampians Group outcrops at Mt Bepcha, western Victoria, represent a prograding fluviodeltaic sequence comprising four lithofacies and five ichnofacies. The stratigraphically lowest Interbedded Sandstone/Siltstone Facies is characterised by thin sandstone and siltstone beds with soft-sediment deformation and scours with gravelly lag deposits. This lithofacies contains Thalassinoides, Palaeophycus, Rhizocorallium and intrastratal burrows, together indicative of the Cruziana Ichnofacies, and is interpreted as a shallow-marine depositional environment on a low-energy delta front with minor tidal influences. The overlying Massive Sandstone Facies lacks silt, and consists of predominantly massive and some plane-laminated sandstone, abundant Skolithos linearis , rare Palaeophycus and a single small Cruziana problematica ; the trace-fossil assemblage is assigned to the Skolithos Ichnofacies. This facies is believed to have been deposited in a marine high-energy shoreface environment with continuously shifting sands, affected by periodic flooding events from the mouth of a nearby river. Above this is the Trough Cross-bedded Facies, which contains trough cross-bedding with gravelly lag deposits, a northwest palaeocurrent direction and large Taenidium barretti burrows (Burrowed Ichnofacies). This facies also contains abundant plane-laminated sandstone with a northeast-southwest palaeocurrent direction and ichnofossils of Scoyenia and Daedalus , representing the Scoyenia Ichnofacies. The Trough Cross-bedded Facies is interpreted to have been deposited in shallow low-sinuosity channels by overbank-flooding events, most likely on a delta plain. The uppermost facies, the Plane-laminated Facies, contains thin beds of current-lineated, plane-laminated graded coarse to fine sandstone that preserve arthropod trackways (Arthropod Ichnofacies). This facies was deposited on a periodically sheet-flooded, subaerially exposed delta plain.

Apparently, they found potential tetrapods trackways there. In the Mid Silurian. They were supposed to be very questionable. Not so much now. The authors of the polish trackways make a call not to dismiss these in light of the very nice and very derived trackways in the Holy Cross Mountains.

a, Muz. PGI 1728.II.16. (Geological Museum of the Polish Geological Institute). Trackway showing manus and pes prints in diagonal stride pattern, presumed direction of travel from bottom to top. A larger print (vertical hatching) may represent a swimming animal moving from top to bottom. b, On the left is a generic Devonian tetrapod based on Ichthyostega and Acanthostega (from ref. 18) fitted to the trackway. On the right, Tiktaalik (from ref. 29 with tail reconstructed from Panderichthys23) is drawn to the same shoulder–hip length. Positions of pectoral fins show approximate maximum ‘stride length’. c, Muz. PGI 1728.II.15. Trackway showing alternating diagonal and parallel stride patterns. In a and c, photographs are on the left, interpretative drawings are on the right. Thin lines linking prints indicate stride pattern. Dotted outlines indicate indistinct margins and wavy lines show the edge of the displacement rim. Scale bars, 10 cm.

A set of fossilized footprints pictured in the scientific journal Nature show the first tetrapods — a term applied to any four-footed animal with a spine — were waddling ashore 397 million years ago, well before scientists thought they existed.

An expert unconnected with the research said the find would force experts to reconsider a critical period in evolution when sea-based vertebrates took their first steps toward becoming dinosaurs, mammals, and — eventually — human beings.

"It blows the whole story out of the water, so to speak," said Jenny Clack, a paleontologist at Cambridge University.

Until now, scientists through they had the evolution from fin to foot fairly well understood. The earliest tetrapods had been traced to 385 million years ago. Experts theorized that they had split from their close relatives, a fleshy-finned family of fish known as Elpistostealians, a few million years earlier and then gone on to conquer land.

But the new fossil footprints — uncovered between 2002 and 2007 in a disused quarry in central Poland — push the timing back by several million years, according to Grzegorz Pienkowski, the scientific director of the Polish Geological Institute in Warsaw, where most of the article's authors are based. He said the fossils had been securely dated from the deposits they were found with.

Pienkowski said that the footprints were first created in what was probably a lagoon-like environment at the time — arguing against the commonly accepted notion that fish came ashore from lakes or rivers.

Pienkowski said such a coastal location made sense because shifting tides could strand small marine animals, giving our fishy forebears an incentive to explore open land.

Clack said the new fossils would force scientists — herself included — to reconsider what it was that originally turned fish into land-lovers.

She said some theorized that tetrapods originally went ashore to lay their eggs out of reach of water-going predators or that their ancestors grew legs to scurry from pool to pool. She said she had personally favored the notion that fish emerged from oxygen-deprived waters in order, quite literally, to catch their breath.

None of those theories was supported by the Polish find, she said.

It wouldn't be logical for fish to lay their eggs in a place where the tide would wash right over them, for example, and the pool-hopping behavior wouldn't make sense in a coastal environment. As for her oxygen hypothesis, Clack said "that's probably out the window." The fossils suggested that tetrapods evolved well before marine oxygen levels started to drop, she said.

Nevertheless, Clack warned against relying exclusively on the marks left by a small animal on the bottom of a muddy surface hundreds of millions of years ago. She said it would be critical to see fossil evidence of the creature that made the footprints before coming to any definitive conclusion on exactly how, when and where vertebrates came to colonize the earth's surface.

Correspondence to: Per E. Ahlberg(D) Correspondence and requests for materials should be addressed to P.E.A. (Email: per.ahlberg@ebc.uu.se).

Abstract:

The fossil record of the earliest tetrapods (vertebrates with limbs rather than paired fins) consists of body fossils and trackways. The earliest body fossils of tetrapods date to the Late Devonian period (late Frasnian stage) and are preceded by transitional elpistostegids such as Panderichthys and Tiktaalik that still have paired fins. Claims of tetrapod trackways predating these body fossils have remained controversial with regard to both age and the identity of the track makers. Here we present well-preserved and securely dated tetrapod tracks from Polish marine tidal flat sediments of early Middle Devonian (Eifelian stage) age that are approximately 18 million years older than the earliest tetrapod body fossils and 10 million years earlier than the oldest elpistostegids. They force a radical reassessment of the timing, ecology and environmental setting of the fish–tetrapod transition, as well as the completeness of the body fossil record.

The volcanic eruptions thought responsible for Earth's largest mass extinction — which killed more than 70 percent of plants and animals 250 million years ago — is still taking lives today. That's the conclusion of a new study showing, for the first time, that the high silica content of coal in one region of China may be interacting with volatile substances in the coal to cause unusually high rates of lung cancer. The study, which helps solve this cancer mystery, appears in ACS' Environmental Science & Technology, a semi-monthly publication.

David Large and colleagues note that parts of China's Xuan Wei County in Yunnan Province have the world's highest incidence of lung cancer in nonsmoking women — 20 times higher than the rest of China. Women in the region heat their homes and cook on open coal-burning stoves that are not vented to the outside. Scientists believe that indoor emissions from burning coal cause cancer, but are unclear why the lung cancer rates in this region are so much higher than other areas. Earlier studies show a strong link between certain volatile substances, called PAHs, in coal smoke and lung cancer in the region.

The scientists found that coal used in parts of Xuan Wei County had about 10 times more silica, a suspected carcinogen, than U.S. coal. Silica may work in conjunction with PAHs to make the coal more carcinogenic, they indicate. The scientists also found that this high-silica coal was formed 250 million years ago, at a time when massive volcanic eruptions worked to deposit silica in the peat that formed Xuan Wei's coal.

Wait. Coal from the PT Boundary?! Uh. Has a paleo type checked into this? It has nontrivial implications for the models for the PT Boundary paeloenvironment. AFAIK, there shouldn't be coal.

When scientists confirmed in October that they had detected the first rocky planet outside our solar system, it advanced the longtime quest to find an Earth-like planet hospitable to life.

Rocky planets – Earth, Mercury, Venus and Mars – make up half the planets in our solar system. Rocky planets are considered better environments to support life than planets that are mainly gaseous, like the other half of the planets in our system: Jupiter, Saturn, Uranus and Neptune.

The rocky planet CoRoT-7 b was discovered circling a star some 480 light years from Earth. It is, however, a forbidding place and unlikely to harbor life. That's because it is so close to its star that temperatures might be above 4,000 degrees F (2,200 C) on the surface lit by its star and as low as minus 350 F (minus 210 C) on its dark side.

Now scientists led by a University of Washington astronomer say that if CoRoT-7 b's orbit is not almost perfectly circular, then the planet might also be undergoing fierce volcanic eruptions. It could be even more volcanically active than Jupiter's moon Io, which has more than 400 volcanoes and is the most geologically active object in our solar system.

"If conditions are what we speculate, then CoRoT-7 b could have multiple volcanoes going off continuously and magma flowing all over the surface," says Rory Barnes, a UW postdoctoral researcher of astronomy and astrobiology. Any planet where the surface is being remade at such a rate is a place nearly impossible for life to get a foothold, he says.

Calculations about CoRoT-7 b's orbit and probable volcanism were presented at the American Astronomical Society meeting in Washington, D.C., during a session Jan. 5 and as part of a press briefing Jan. 6. CoRoT-7 b was discovered by a French-led team using the CoRoT – Convection, Rotation and Planetary Transits – satellite.

The next step to finding a planet that harbors life may have to wait until astronomers are better able to detect rocky planets that are farther from their stars, Barnes says. "Because it is easier to detect planets that orbit close to their host stars, a significant fraction of the first wave of rocky planets being found outside our solar system may be more Io-like than Earth-like."

Barnes and his colleagues suspect CoRoT-7 b is subject to extreme volcanism partly because it is so close to its sun, the distance between the two being about 1.6 million miles (2.5 million kilometers). That's about 60 times closer than the Earth is to the sun.

Volcanism is then triggered by even a tiny deviation from a circular orbit. How tiny of a deviation? About 155 miles (250 kilometers), according to calculations done by Barnes based on how bodies in our solar system influence each other's orbits. That's about the distance from Washington, D.C., to Philadelphia. That amount of deviation, or more, could be caused by the gravitational pull of the next planet out from CoRoT-7 b.

Deviations in its orbit would set tidal forces in motion that flex and distort the whole shape of CoRoT-7 b. This is different from what happens on Earth, where oceans absorb the energy of tidal forces.

"CoRoT-7 b most certainly has no oceans. A planet on a non-circular orbit experiences different amounts of gravitational force at different points along the orbit, feeling the strongest gravitational pull when it is closest to the star and the weakest when it is most distant. As the planet moves between these two points, it stretches and relaxes. This flexing produces friction that heats the interior of the planet resulting in volcanism on the surface," Barnes says.

"This scenario is exactly what is occurring on Jupiter's moon Io. For planets like CoRoT-7 b, however, the heating may be much, much stronger than on Io."

Not exactly what's happening on Io (no orbital resonances, AFAIK), but point taken.

Tuesday, January 05, 2010

Global Taxonomic Diversity of Anomodonts (Tetrapoda, Therapsida) and the Terrestrial Rock Record Across the Permian-Triassic Boundary

Jörg Fröbisch (1,*)

1. Department of Biology, University of Toronto, Mississauga, Ontario, Canada

* E-mail: jorg.frobisch@utoronto.caAbstract:

The end-Permian biotic crisis (~252.5 Ma) represents the most severe extinction event in Earth's history. This paper investigates diversity patterns in Anomodontia, an extinct group of therapsid synapsids (‘mammal-like reptiles’), through time and in particular across this event. As herbivores and the dominant terrestrial tetrapods of their time, anomodonts play a central role in assessing the impact of the end-Permian extinction on terrestrial ecosystems. Taxonomic diversity analysis reveals that anomodonts experienced three distinct phases of diversification interrupted by the same number of extinctions, i.e. an end-Guadalupian, an end-Permian, and a mid-Triassic extinction. A positive correlation between the number of taxa and the number of formations per time interval shows that anomodont diversity is biased by the Permian-Triassic terrestrial rock record. Normalized diversity curves indicate that anomodont richness continuously declines from the Middle Permian to the Late Triassic, but also reveals all three extinction events. Taxonomic rates (origination and extinction) indicate that the end-Guadalupian and end-Permian extinctions were driven by increased rates of extinction as well as low origination rates. However, this pattern is not evident at the final decline of anomodont diversity during the Middle Triassic. Therefore, it remains unclear whether the Middle Triassic extinction represents a gradual or abrupt event that is unique to anomodonts or more common among terrestrial tetrapods. The end-Permian extinction represents the most distinct event in terms of decline in anomodont richness and turnover rates.